Land Sea Masking Scripts

Matlab: Land/Sea Masking Scripts

This page describes several Matlab scripts in the matlab/landmask repository sub-directory, which are used to process ROMS Land/Sea mask.

add_coastline.m

Adds coastline data to ROMS Grid NetCDF file. This is the coastline data is used to facilitate Land/Sea masking editing.

add_coastline  (ncfile, Clon, Clat)

On Input:

ncfile:   ROMS Grid NetCDF file name (string)

Clon :   Coastline longitude (1D array, degree_east)

Clat :   Coastline latitude (1D array, degree_north)

editmask.m

GUI for manual editing of ROMS Land/Sea mask on RHO-points. To accelerate the processing, the Land/Sea mask is edited in (I,J) grid coordinates. If the (I,J) coordinates are not provided, it compute and write them into file. If called without, one or both arguments, it will prompt for the needed file name(s). If the coastline data is in grid_file, it will read it and convert to (I,J) fractional coordinates.

editmask  (grid_file, coast_file)

On Input:

grid_file :   ROMS Grid NetCDF file name containing the grid and mask arrays (string)

coast_file:   Matlab file name containing the coastline (lon, lat) or (I,J) fractional coordinates (string; optional)

Mouse shortcuts:

double click,   zoom in

right click,   zoom out

middle click,   change editing mode

editscope.m

GUI for manual editing of ROMS adjoint sensitivity scope mask on RHO-points. To accelerate the processing, the Land/Sea mask is edited in (I,J) grid coordinates. If the (I,J) coordinates are not provided, it compute and write them into file. If called without, one or both arguments, it will prompt for the needed file name(s). If the coastline data is in grid_file, it will read it and convert to (I,J) fractional coordinates.

editscope  (grid_file, coast_file)

On Input:

grid_file :   ROMS Grid NetCDF file name containing the grid and mask arrays (string)

coast_file:   Matlab file name containing the coastline (lon, lat) or (I,J) fractional coordinates (string; optional)

Mouse shortcuts:

double click,   zoom in

right click,   zoom out

middle click,   change editing mode

ijcoast.m

Converts coastline data to ROMS (I,J) fractional coordinates to facilitate Land/Sea masking editing with editmask.

C = ijcoast  (ncfile, coast_file)

On Input:

ncname:   ROMS grid NetCDF file name (string)

coast_file:   Coastline file name (string)

On Output:

C:   Coastline data (struct array)

C.grid ,   ROMS Grid NetCDF file name

C.coast ,   Coastline file name

C.indices,   Coastline indices file name

C.lon ,   Coastline longitudes

C.lat ,   Coastline latitudes

C.Icst ,   Coastline I-grid coordinates, (0:L)

C.Jcst ,   Coastline J-grid coordinates, (0:M)

landsea.m

Computes automatically the Land/Sea mask for an application grid and writes it into input NetCDF file. The Land/Sea mask is computed from closed coastlines polygons extracted from the GSHHS data set if the (clon, clat) coastline data is not provided.

F = lansea  (ncfile, clon, clat)

On Input:

ncname:   ROMS grid NetCDF file name (string)

clon :   Coastline longitude (1D array; degrees_west)

clat :   Coastline latitude (1D array; degrees_north)

On Output:

F:   Land/Sea mask data (struct array)

F.mask_rho,   Mask on ρ-points (2D array)

F.mask_psi,   Mask on ψ-points (2D array)

F.mask_u ,   Mask on u-points (2D array)

F.mask_v ,   Mask on v-points (2D array)

read_mask.m

Reads in ROMS grid bathymetry and Land/Sea mask at ρ-point from NetCDF file.

[spherical, x, y, bath, rmask] = read_mask  (ncfile)

On Input:

ncname:   ROMS grid NetCDF file name (string)

On Output:

spherical,   Spherical switch (logical)

x ,   X-location of ρ-points

y ,   Y-location of ρ-points

bath ,   Bathymetry at ρ-points

rmask ,   Land/Sea mask at ρ-points

read_scope.m

Reads in ROMS grid bathymetry and adjoint sensitivity scope mask at ρ-point from NetCDF file.

[spherical, x, y, bath, rmask] = read_mask  (ncfile)

On Input:

ncname:   ROMS grid NetCDF file name (string)

On Output:

spherical,   Spherical switch (logical)

x ,   X-location of ρ-points

y ,   Y-location of ρ-points

bath ,   Bathymetry at ρ-points

rmask ,   Land/Sea mask at ρ-points

uvp_masks.m

Computes the Land/Sea masks at u-, v-, and ψ-points from the mask on ρ-points.

[umask, vmask, vmask] = uvp_masks  (rmask)

On Input:

rmask:   Land/Sea mask on ρ-points (2D array)

On Output:

umask,   Land/Sea mask on u-points (2D array)

vmask,   Land/Sea mask on v-points (2D array)

rmask,   Land/Sea mask on ψ-points (2D array)

uv_scope.m

Computes the adjoint sensitivity scope masks at u- and v-points from the scope mask on ρ-points.

[Uscope, Vscope] = uvp_masks  (Rscope)

On Input:

Rscope:   Scope mask on ρ-points (2D array)

On Output:

Uscope,   Scope mask on u-points (2D array)

Vscope,   Scope mask on v-points (2D array)

write_mask.m

Writes out Land/Sea mask data into ROMS Grid NetCDF file.

span class="green">status = write_mask  (ncfile, span class="green">rmask, umask, vmask, pmask)

On Input:

ncname:   ROMS grid NetCDF file name (string)

rmask ,   Land/Sea mask on ρ-points (2D array)

umask ,   Land/Sea mask on u-points (2D array)

vmask ,   Land/Sea mask on v-points (2D array)

pmask ,   Land/Sea mask on ψ-points (2D array)

On Output:

status,   Error flag

write_scope.m

Writes out adjoint sensitivity scope mask data into ROMS Grid NetCDF file.

span class="green">status = write_mask  (ncfile, span class="green">Rscope, Uscope, Vscope)

On Input:

ncname:   ROMS grid NetCDF file name (string)

Rscope,   Adjoint sensitivity scope mask on ρ-points (2D array)

Uscope,   Adjoint sensitivity scope mask on u-points (2D array)

Vscope,   Adjoint sensitivity scope mask on v-points (2D array)

On Output:

status,   Error flag